1 /* 2 * Copyright (c) 2002, Jeffrey Roberson <jroberson@chesapeake.net> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 * 28 */ 29 30 /* 31 * uma.h - External definitions for the Universal Memory Allocator 32 * 33 * Jeff Roberson <jroberson@chesapeake.net> 34 */ 35 36 #ifndef VM_UMA_H 37 #define VM_UMA_H 38 39 #include <sys/param.h> /* For NULL */ 40 #include <sys/malloc.h> /* For M_* */ 41 42 /* User visable parameters */ 43 #define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */ 44 45 /* Types and type defs */ 46 47 struct uma_zone; 48 /* Opaque type used as a handle to the zone */ 49 typedef struct uma_zone * uma_zone_t; 50 51 /* 52 * Item constructor 53 * 54 * Arguments: 55 * item A pointer to the memory which has been allocated. 56 * arg The arg field passed to uma_zalloc_arg 57 * size The size of the allocated item 58 * 59 * Returns: 60 * Nothing 61 * 62 * Discussion: 63 * The constructor is called just before the memory is returned 64 * to the user. It may block if neccisary. 65 */ 66 typedef void (*uma_ctor)(void *mem, int size, void *arg); 67 68 /* 69 * Item destructor 70 * 71 * Arguments: 72 * item A pointer to the memory which has been allocated. 73 * size The size of the item being destructed. 74 * arg Argument passed through uma_zfree_arg 75 * 76 * Returns: 77 * Nothing 78 * 79 * Discussion: 80 * The destructor may perform operations that differ from those performed 81 * by the initializer, but it must leave the object in the same state. 82 * This IS type stable storage. This is called after EVERY zfree call. 83 */ 84 typedef void (*uma_dtor)(void *mem, int size, void *arg); 85 86 /* 87 * Item initializer 88 * 89 * Arguments: 90 * item A pointer to the memory which has been allocated. 91 * size The size of the item being initialized. 92 * 93 * Returns: 94 * Nothing 95 * 96 * Discussion: 97 * The initializer is called when the memory is cached in the uma zone. 98 * this should be the same state that the destructor leaves the object in. 99 */ 100 typedef void (*uma_init)(void *mem, int size); 101 102 /* 103 * Item discard function 104 * 105 * Arguments: 106 * item A pointer to memory which has been 'freed' but has not left the 107 * zone's cache. 108 * size The size of the item being discarded. 109 * 110 * Returns: 111 * Nothing 112 * 113 * Discussion: 114 * This routine is called when memory leaves a zone and is returned to the 115 * system for other uses. It is the counter part to the init function. 116 */ 117 typedef void (*uma_fini)(void *mem, int size); 118 119 /* 120 * What's the difference between initializing and constructing? 121 * 122 * The item is initialized when it is cached, and this is the state that the 123 * object should be in when returned to the allocator. The purpose of this is 124 * to remove some code which would otherwise be called on each allocation by 125 * utilizing a known, stable state. This differs from the constructor which 126 * will be called on EVERY allocation. 127 * 128 * For example, in the initializer you may want to initialize embeded locks, 129 * NULL list pointers, set up initial states, magic numbers, etc. This way if 130 * the object is held in the allocator and re-used it won't be neccisary to 131 * re-initialize it. 132 * 133 * The constructor may be used to lock a data structure, link it on to lists, 134 * bump reference counts or total counts of outstanding structures, etc. 135 * 136 */ 137 138 139 /* Function proto types */ 140 141 /* 142 * Create a new uma zone 143 * 144 * Arguments: 145 * name The text name of the zone for debugging and stats, this memory 146 * should not be freed until the zone has been deallocated. 147 * size The size of the object that is being created. 148 * ctor The constructor that is called when the object is allocated 149 * dtor The destructor that is called when the object is freed. 150 * init An initializer that sets up the initial state of the memory. 151 * fini A discard function that undoes initialization done by init. 152 * ctor/dtor/init/fini may all be null, see notes above. 153 * align A bitmask that corisponds to the requested alignment 154 * eg 4 would be 0x3 155 * flags A set of parameters that control the behavior of the zone 156 * 157 * Returns: 158 * A pointer to a structure which is intended to be opaque to users of 159 * the interface. The value may be null if the wait flag is not set. 160 */ 161 162 uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor, 163 uma_init uminit, uma_fini fini, int align, 164 u_int16_t flags); 165 166 /* Definitions for uma_zcreate flags */ 167 #define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by 168 physical memory XXX Not yet */ 169 #define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */ 170 #define UMA_ZONE_STATIC 0x0004 /* Staticly sized zone */ 171 #define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation 172 off of the real memory */ 173 #define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */ 174 #define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */ 175 #define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */ 176 #define UMA_ZONE_VM 0x0080 /* 177 * Used for internal vm datastructures 178 * only. 179 */ 180 #define UMA_ZONE_HASH 0x0100 /* 181 * Use a hash table instead of caching 182 * information in the vm_page. 183 */ 184 185 /* Definitions for align */ 186 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */ 187 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */ 188 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */ 189 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */ 190 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */ 191 #define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */ 192 193 /* 194 * Destroys an empty uma zone. If the zone is not empty uma complains loudly. 195 * 196 * Arguments: 197 * zone The zone we want to destroy. 198 * 199 */ 200 201 void uma_zdestroy(uma_zone_t zone); 202 203 /* 204 * Allocates an item out of a zone 205 * 206 * Arguments: 207 * zone The zone we are allocating from 208 * arg This data is passed to the ctor function 209 * flags See sys/malloc.h for available flags. 210 * 211 * Returns: 212 * A non null pointer to an initialized element from the zone is 213 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be 214 * returned if the zone is empty or the ctor failed. 215 */ 216 217 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags); 218 219 /* 220 * Allocates an item out of a zone without supplying an argument 221 * 222 * This is just a wrapper for uma_zalloc_arg for convenience. 223 * 224 */ 225 static __inline void *uma_zalloc(uma_zone_t zone, int flags); 226 227 static __inline void * 228 uma_zalloc(uma_zone_t zone, int flags) 229 { 230 return uma_zalloc_arg(zone, NULL, flags); 231 } 232 233 /* 234 * Frees an item back into the specified zone. 235 * 236 * Arguments: 237 * zone The zone the item was originally allocated out of. 238 * item The memory to be freed. 239 * arg Argument passed to the destructor 240 * 241 * Returns: 242 * Nothing. 243 */ 244 245 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg); 246 247 /* 248 * Frees an item back to a zone without supplying an argument 249 * 250 * This is just a wrapper for uma_zfree_arg for convenience. 251 * 252 */ 253 static __inline void uma_zfree(uma_zone_t zone, void *item); 254 255 static __inline void 256 uma_zfree(uma_zone_t zone, void *item) 257 { 258 uma_zfree_arg(zone, item, NULL); 259 } 260 261 /* 262 * XXX The rest of the prototypes in this header are h0h0 magic for the VM. 263 * If you think you need to use it for a normal zone you're probably incorrect. 264 */ 265 266 /* 267 * Backend page supplier routines 268 * 269 * Arguments: 270 * zone The zone that is requesting pages 271 * size The number of bytes being requested 272 * pflag Flags for these memory pages, see below. 273 * wait Indicates our willingness to block. 274 * 275 * Returns: 276 * A pointer to the alloced memory or NULL on failure. 277 */ 278 279 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait); 280 281 /* 282 * Backend page free routines 283 * 284 * Arguments: 285 * item A pointer to the previously allocated pages 286 * size The original size of the allocation 287 * pflag The flags for the slab. See UMA_SLAB_* below 288 * 289 * Returns: 290 * None 291 */ 292 typedef void (*uma_free)(void *item, int size, u_int8_t pflag); 293 294 295 296 /* 297 * Sets up the uma allocator. (Called by vm_mem_init) 298 * 299 * Arguments: 300 * bootmem A pointer to memory used to bootstrap the system. 301 * 302 * Returns: 303 * Nothing 304 * 305 * Discussion: 306 * This memory is used for zones which allocate things before the 307 * backend page supplier can give us pages. It should be 308 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h) 309 * 310 */ 311 312 void uma_startup(void *bootmem); 313 314 /* 315 * Finishes starting up the allocator. This should 316 * be called when kva is ready for normal allocs. 317 * 318 * Arguments: 319 * None 320 * 321 * Returns: 322 * Nothing 323 * 324 * Discussion: 325 * uma_startup2 is called by kmeminit() to enable us of uma for malloc. 326 */ 327 328 void uma_startup2(void); 329 330 /* 331 * Reclaims unused memory for all zones 332 * 333 * Arguments: 334 * None 335 * Returns: 336 * None 337 * 338 * This should only be called by the page out daemon. 339 */ 340 341 void uma_reclaim(void); 342 343 /* 344 * Switches the backing object of a zone 345 * 346 * Arguments: 347 * zone The zone to update 348 * obj The obj to use for future allocations 349 * size The size of the object to allocate 350 * 351 * Returns: 352 * 0 if kva space can not be allocated 353 * 1 if successful 354 * 355 * Discussion: 356 * A NULL object can be used and uma will allocate one for you. Setting 357 * the size will limit the amount of memory allocated to this zone. 358 * 359 */ 360 struct vm_object; 361 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size); 362 363 /* 364 * Sets a high limit on the number of items allowed in a zone 365 * 366 * Arguments: 367 * zone The zone to limit 368 * 369 * Returns: 370 * Nothing 371 */ 372 void uma_zone_set_max(uma_zone_t zone, int nitems); 373 374 /* 375 * Replaces the standard page_alloc or obj_alloc functions for this zone 376 * 377 * Arguments: 378 * zone The zone whos back end allocator is being changed. 379 * allocf A pointer to the allocation function 380 * 381 * Returns: 382 * Nothing 383 * 384 * Discussion: 385 * This could be used to implement pageable allocation, or perhaps 386 * even DMA allocators if used in conjunction with the OFFPAGE 387 * zone flag. 388 */ 389 390 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf); 391 392 /* 393 * Used for freeing memory provided by the allocf above 394 * 395 * Arguments: 396 * zone The zone that intends to use this free routine. 397 * freef The page freeing routine. 398 * 399 * Returns: 400 * Nothing 401 */ 402 403 void uma_zone_set_freef(uma_zone_t zone, uma_free freef); 404 405 /* 406 * These flags are setable in the allocf and visable in the freef. 407 */ 408 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */ 409 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */ 410 #define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */ 411 #define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */ 412 #define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */ 413 /* 0x40 and 0x80 are available */ 414 415 /* 416 * Used to pre-fill a zone with some number of items 417 * 418 * Arguments: 419 * zone The zone to fill 420 * itemcnt The number of items to reserve 421 * 422 * Returns: 423 * Nothing 424 * 425 * NOTE: This is blocking and should only be done at startup 426 */ 427 void uma_prealloc(uma_zone_t zone, int itemcnt); 428 429 430 #endif 431